I'd say Wind Waker; it's much better than Twilight Princess. As for a more approachable one? If you've already beaten Ocarina of Time, try Majora's Mask. It's MUCH more difficult and definitely way shorter than Ocarina, but it's so much better than most other Zelda games in almost every way.

Personally, I prefer Link to the Past myself, but I also have a soft spot for Adventure of Link and the Original as well.

That said, Wind Waker is probably the better choice for you. Very straight forward, and not a lot to confuse you with. However the beginning starts off pretty slowly with that mandatory stealth sequence, and sailing around is kinda clumsy and takes a while. Also look up the Wind Waker manga after you're done. The way they reinterpret many of the scenes in the game are down right hilarious.

Twilight Princess was kinda disappointing to me. Aside from the glacial pace of the opening, there's the fact that it's big gimmick was to swipe from LttP, OoT, & MM's gimmicks. Also the items of the game were about as useful as the boss weapons in Megaman X3 (in that they're there, and you'll need them for when they are needed, but you'll otherwise be sticking to your main weapons in every other case). That said, the later dungeons ARE good and do interesting things, but its just that the overworld is a lot larger and emptier than it needed to be. Also the plot kinda jumps rails around level 4 and what was an otherwise interesting take on Zelda became more of the same.